BOISE, Idaho — In the search for missing Fruitland boy Michael Vaughan, cadaver dogs hit on a scent in the yard of murder suspect Stacey Wondra...but the dig turned up nothing. I’m senior reporter Roland Beres asking: When there’s no body, just how much weight does cadaver dog evidence carry in a murder case?
There’s no question, this is a talented nose.
“A dog has 250 to 300 million scent receptor cells. We have about 5 million." says Julie Gibson, President of Mountain States Detection Dogs.
Watch to learn more about how cadaver dogs are trained —
Yonni is one of her cadaver dogs. He’s trained to detect, or "hit" on odors from dead bodies.
“We start our dogs as puppies. And they're only imprinted on human remains scent," says Gibson.
And throughout history there’s a long list of court cases where cadaver dogs like Yonni have found actual physical evidence, like a body, that helped lead to a conviction.
But what about cases where a dog hits on a scent but nothing is found?
I asked Binyamin Blum, Law Professor and evidence expert at UC SanFrancisco, “Well they’re very problematic because they raise a lot of complications in how we generally approach evidence. The thing is we don’t get to cross examine the dog. Every criminal defendant should be allowed to confront their accusers. And again there’s no way a defendant can confront a dog that has identified them as a culprit.”
Despite that, he says, cadaver dog actions can carry lots of weight in court.
“That kind of evidence is very compelling it is able to sway a jury particularly if this is a heinous crime where the public is eager to find a culprit and this is all the evidence we have to hang on to,” explains Blum.
I asked Gibson if there's a predisposition in court cases to accept dog sniff evidence.
"No, I do not," Gibson said. "I think in court it's our job to prove that our dogs are correct."
She’s worked with scent dogs for 33 years and she says she keeps impeccable records because showing her regular training routine is key to credibility in the courtroom.
Her dogs practice regularly on things like finding buried human remains or residual scent in vehicles.
But her methodology may not be the same as another trainer. In fact, there are three main certification boards to train cadaver dogs across the US which is something that worries Blum.
“Until we fully understand how dogs work and how their sense of smell works, we should probably keep them away from juries,” says Blum.
Gibson is confident in the ability of her dogs, but leaves it up to the courts how much weight they should carry in a circumstantial murder case. "Honestly, it would depend," explains Gibson. "I mean, there are a lot of circumstances that go with that.”
There are new developments in technology that may someday allow a machine to confirm scent findings from cadaver dogs.
But until they are proven to work, it will have to remain up to the judges and juries how much stock to put into irrefutable testimony
